导图社区 unit 8
计算机网络基础,整理有: 1.What is a computer network 2.Components of Computer Network 3.Uses of Computer Network 4.Computer Network Architecture...
编辑于2023-04-02 15:26:11 福建省Computer Network Basic
1.What is a computer network
computers connected with each other through wires, can interact with each other through a network, to share resources among various devices.
2.Components of Computer Network
NIC
helps the computer to communicate with another device.
two types
Wireless NIC
All the modern laptops use the wireless NIC. that employs the radio wave technology.
Wired NIC
Cables use the wired NIC to transfer the data over the medium.
Hub
central device that splits the network connection into multiple devices.
Switch
networking device that groups all the devices over the network to transfer the data to another device.
Cable
transmission media that transmits the communication signals.
Twisted pair cable: high-speed cable that transmits the data over 1Gbps or more.
Coaxial cable: like a TV installation cable. It is more expensive than twisted pair cable, but it provides the high data transmission speed.
Fibre optic cable: It is a high-speed cable that transmits the data using light beams. It provides higher data transmission speed as compared to other cables. It is more expensive as compared to other cables.
Router
a device that connects the LAN to the internet. The router is mainly used to connect the distinct networks or connect the internet to multiple computers.
3.Uses of Computer Network
Resource sharing:
the sharing of resources such as programs, printers, and data among the users on the network without the requirement of the physical location of the resource and user.
Server-Client model:
A server is a central computer used to store the information and maintained by the system admin- istrator. Clients are the machines used to access the information stored in the server remotely.
Communication medium:
Computer network behaves as a communication medium among the users.
commerce:
People can do business over the internet.
4.Computer Network Architecture
defined as the physical and logical design of the software,hardware, protocols, and media of the transmission of data.
Peer-to-Peer Network
is a network, useful for small environments, usually up to 10 computers. no dedicated server.
Advantages
does not contain any dedicated server. less costly
each computer manages itself. easy to set up and maintain
Disadvantages
does not contain the centralized system. cannot back up the data as the data is different in different locations.
has a security issue as the device
Client/Server Network
model designed for the end users called clients,A server performs all the major operations such as security and network management.
Advantages
can back up the data easily.
improves the overall performance of the whole system.
Security is better in client/server network
increases the speed of the sharing resources.
Disadvantages
expensive as it requires the server with large memory.
the cost of NOS is very high.
requires a dedicated network administrator to manage all the resources.
5. Features of Computer Network
Communication Speed
File Sharing
Easy Back up
Software and Hardware Sharing
Security
Scalability
Reliability
6. Computer Network Types
LAN (Local Area Network)
group of computers connected to each other in a small area
MAN (Metropolitan Area Network)
covers a larger geographic area by intercon- necting different LANs to form a larger network.
Uses
communication between the banks in a city.
an airline reservation.
college within a city.
WAN (Wide Area Network)
a network that extends over a large geographical area such as states or countries.
Examples
Mobile broadband
Last mile
Private network
Advantages
Geographical area:
Centralized data:
Get updated files:
Exchange messages:
Sharing of software and resources:
Global business:
Disadvantages
Security issue
Need of firewall and antivirus software
High setup cost
Troubleshooting problems
Internetwork
An internetwork is defined as two or more LANs or WANs or computer network segments Which are connected using devices
two types
extranet:a communication network based on the internet protocol
intranet:a private network based on the internet protocol.